Three major short chain fatty acids (SCFA) produced in the human gastrointestinal tract are acetate, propionate, and butyrate. The growth of bacteria, primarily Bifidobacterium and Lactobacillus, is stimulated by the presence of non-digestible food whose fermentative action produce SCFA's (Wong J M, de Souza R, Kendall C W, Emam A, Jenkins D J, Colonic health: Fermentation and short chain fatty acids , J Clin Gastroenterol., 2006; 40(3):235). Butyrate is responsible for various beneficial health effects, including improvement of the intestinal structure of piglets with short-bowel syndrome (Bartholome A L, Albin D M, Baker D H, Holst J J, Tappenden K A, Supplementation of total parenteral nutrition with butyrate acutely increases structural aspects of intestinal adaptation after an 80% jejunoileal resection in neonatal piglets J of Parenter Enteral Nutr. 2004; 28(4):210-222), decreasing the proliferation of colon cancer cells in human cell lines (Lupton J R., Microbial degradation products influence colon cancer risk: The butyrate controversy , J Nutr., 2004; 134(2):479-482), decreasing the incidence of diarrhea (Berni Canani R, Terrin G, Cirillo P, et al., Butyrate as an effective treatment of congenital chloride diarrhea, Gastroenterol., 2004; 127(2):630-634), improvement in inflammatory bowel disease (Scarpellini E, Lauritano E C, Lupascu A, et al., Efficacy of butyrate in the treatment of diarrhoea -predominant irritable bowel syndrome , Dig Liver Dis., 2007; 1(1):19-22) and small intestine health (Kotunia A, Woliński J, Laubitz D, et al., Effect of sodium butyrate on the small intestine development in neonatal piglets fed [correction of feed] by artificial sow , J Physiol Pharmacol. 1994; 55(2):59-68).
Tributyrin is compound that contains, and is a source of, butyric acid; a naturally produced short chain fatty acid related to the maintenance of intestinal health and associated with the improvement of some intestinal disease states. Tributyrin is a triglyceride that contains three moles of butyric acid per mole of tributyrin. Tributyrin is a food additive that is generally regarded as safe (GRAS) (21CFR184.1903), and is a natural component of many dairy items. Tributyrin is rapidly absorbed and chemically stable in plasma where it is converted into butyric acid by intracellular lipases to elicit its beneficial effects (Gaschott T, Steinhilber D, Milovic V, Stein J., Tributyrin, a stable and rapidly absorbed prodrug of butyric acid, enhances antiproliferative effects of dihydroxycholecalciferol in human colon cancer cells, Nutr Cancer, 2001; 131(6):1839-1843). A more immediate release and conversion of tributyrin to butyric acid in the intestinal tract can be achieved with exposure to pancreatic, gastric, or other lipases and esterases (Leonel A J, Alvarez-Leite J I, Butyrate: Implications for intestinal function, Curr Opin Clin Nutr Metab Care, 2012; 15(5):474-479; O'Connor K C, Bailey J E, Hydrolysis of emulsified tributyrin by porcine pancreatic lipase , Enzyme Microb Technol., 1988; 10(6):352-356). Aside from its conversion to butyrate to elicit beneficial effects, the administration of tributyrin both in-vitro and in-vivo has led to improvement in small intestinal structures (Gaschott, supra), and inhibited growth of colon cancer cell lines (Li Y, Le Maux S, Xiao H, McClements D J, 2009, Emulsion-based delivery systems for tributyrin, a potential colon cancer preventative agent, J Agric Food Chem 57(19):9243-9).
However, Tributyrin is associated with negative sensory qualities including high bitterness and aroma attributes, such as vomit-like, fecal, and cheesy. Characterized by unpleasant odor and taste, its use in food as a functional ingredient poses a challenge.
Inflammatory bowel disease (IBD) refers to two chronic diseases that cause inflammation of the intestines: ulcerative colitis and Crohn's disease. Whereas ulcerative colitis is an inflammatory disease of the large intestine that affects the mucosa of the intestine which becomes inflamed and develops ulcers, Crohn's disease most commonly affects the last part of the small intestine, the terminal ileum, and parts of the large intestine. However, Crohn's disease is not limited to these areas and can occur in any part of the digestive tract. Crohn's disease causes inflammation that extends much deeper into the layers of the intestinal wall than ulcerative colitis does. Crohn's disease generally tends to involve the entire bowel wall, whereas ulcerative colitis affects only the lining of the bowel.
Medical research has not determined yet what causes inflammatory bowel disease. It has been postulated that a number of factors may be involved, such as the environment, diet, and possibly genetics. The drug treatment for IBD usually consists of anti-inflammatory drugs and immunosuppressive agents. However, current therapy to control IBD is not always effective, and surgical procedures are necessary in many cases. Today, about 70 to 80% of patients with Crohn's disease and about 30 to 40% with ulcerative colitis ultimately require surgery, indicating the lack of efficiency of the currently used therapeutics.
Colorectal cancer is the second most common cause of new cancer cases and cancer deaths in the United States, with an estimated 146,940 new cases and 56,730 deaths in 2004 (Jemal, A, Tiwari, R C, Murray, T, Ghafoor, A, Samuels, A, Ward, E, Feuer, E J and Thun, M J, Cancer Statistics, 2004, CA: A Cancer Journal for Clinicians, 54: 8-29). It has been suggested that a significant fraction of colon cancers could be prevented by moderate changes in diet and lifestyle. Epidemiological and experimental studies suggest that dietary fiber is protective against the development of colon cancer, with these effects being mainly attributed to the production of short-chain fatty acids. For many years, butyric acid, an important short-chain fatty acid produced by dietary fiber fermentation in the colon, has been investigated for its potential preventive effects. Butyrate has been reported to inhibit cancer cell proliferation and to stimulate the growth of healthy cells. As well as being produced by microbial fermentation of dietary fiber, butyric acid is also found naturally in vegetable oils and animal fats. Although the potential of butyrate as an antitumor agent has been recognized, its application as a therapeutic agent has been hampered because of difficulties in consistently delivering physiologically efficacious concentrations to the site of action, that is, the colon. The poor clinical response has been suggested to be related to butyrate's rapid metabolism and very short half-life in human plasma (<6 min), which causes inability to reach therapeutically effective serum concentrations.
Currently, butyric acid (butyrate) is used in the treatment of IBD, but the actual delivery of butyric acid into the gastrointestinal tract is problematic. Several mechanisms have already been proposed, including the use of butyrate coated tablets, butyrate enemas or the use of natural fermentation in the gastrointestinal tract using dietary fiber. These currently known approaches show significant drawbacks. When using butyric coated tablets, the problem lies in the release of their content at the intended location and because of the inter-individual differences in gastrointestinal tract lumen pH and transit time (Ibekwe V C, Liu F, Fadda H M, Khela M K, Evans D F, Parsons G E, Basit A W, An investigation into the in vivo performance variability of pH responsive polymers for ileo - colonic drug delivery using gamma scintigraphy in humans , J Pharm Sci, 2006; 95:2760-6; Roda A, Simoni P, Magliulo M, Nanni P, Baraldini M, Roda G, Roda E, A new oral formulation for the release of sodium butyrate in the ileo - cecal region and colon, World J Gastroenterol, 2007; 13:1079-84, the release cannot be optimized. Moreover, taste and odor of the tablets is very unpleasant despite being encased in a coating. The use of rectal butyric acid enemas on the other hand is hampered by a low compliance rate and a short and discontinuous exposure of the colon mucosa to butyrate (Breuer R I, Soergel K H, Lashner B A, Christ M L, Hanauer S B, Vanagunas A, Harig J M, Keshavarzian A, Robinson M, Sellin J H, Weinberg D, Vidican D E, Flemal K L, Rademaker A W, 1997, Short chain fatty acid rectal irrigation for left - sided ulcerative colitis: a randomised, placebo controlled trial, Gut 40(4):485-91). When using the fermentation of dietary fiber for butyrate production, the use of resistant starch and oligofructose have been associated with a greater butyrate production (Morrison D J, Mackay W G, Edwards C A, Preston T, Dodson B, Weaver L T, Butyrate production from oligofructose fermentation by the human faecal flora: what is the contribution of extracellular acetate and lactate ?, Br J Nutr., 2006 September; 96(3):570-7). The stimulation of butyrate production, however, depends on the presence of bacteria expressing butyryl CoA:acetyl CoA transferase and the regional differences in lactate utilizing, butyrate producing bacteria (Morrison et. al., supra). Therefore, this approach is not uniform and the outcome cannot be predicted. For the treatment of dysbacteriosis in animals, a powder form or coated butyric acid administration to the feed is used. This results, however, in similar problems as stated above, additionally having a negative sensory aspect that is unfavorable for the animals.
Tributyrin, a prodrug of buytric acid, is a short-chain fatty acid triglyceride that can overcome the disadvantages of butyric acid. Because it is rapidly absorbed and chemically stable in blood plasma, tributyrin diffuses through biological membranes and is metabolized by intracellular lipases, thereby releasing butyrate in therapeutically effective concentrations over time directly into the cell. Previous attempts to enclose tributyrin in a gel capsule or to mask its taste and smell with a flavorant have not satisfactorily overcome the bitter taste and foul odor characteristics.
Cyclodextrins are cyclic oligosaccharides with hydroxyl groups on the outer surface and a void cavity in the center. Their outer surface is hydrophilic, and therefore they are usually soluble in water, but the cavity has a lipophilic character. The most common cyclodextrins are α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin, consisting of 6, 7 and 8 α-1,4-linked glucose units, respectively. The number of these units determines the size of the cavity. Cyclodextrins are capable of forming inclusion complexes with a wide variety of hydrophobic molecules by taking up a whole molecule, or some part of it, into the cavity. The stability of the complex formed depends on how well the guest molecule fits into the cyclodextrin cavity. Common cyclodextrin derivatives are formed by alkylation (e.g., methyl- and ethyl-β-cyclodextrin) or hydroxyalkylation of the hydroxyl groups (e.g., hydroxypropyl- and hydroxyethyl-derivatives of α-, β-, and γ-cyclodextrin) or by substituting the primary hydroxyl groups with saccharides (e.g., glucosyl- and maltosyl-β-cyclodextrin).
Cyclodextrins as wall materials are cyclic structures containing repeating units of glucopyranose connected by α-(1, 4) linkages. They are approved for food use (Del Valle E M M, Cyclodextrins and their uses: A review , Process Biochem., 2004; 39(9):1033-1046) in the US and many other countries. Cyclodextrins are commonly found in 6 (alpha-cyclodextrin), 7 (beta-cyclodextrin), and 8 (gamma-cyclodextrin) repeating units. Cyclodextrins are linked in such a way that they possess a hydrophilic outside and an inner hydrophobic cavity. Complexes are formed when compounds of interest enter the hydrophobic cavity in an energetically favorable reaction (Astray G, Gonzalez-Barreiro C, Mejuto J C, Rial-Otero R, Simal-Gándara J., A review on the use of cyclodextrins in foods , Food Hydrocoll, 2009; 23(7):1631-1640). This inner cavity gives cyclodextrins the ability to serve as microencapsulation substrates for a variety of compounds including pharmaceutical, cosmetic, and food ingredients (Szente L, Szejtli J., Cyclodextrins as food ingredients , Trends Food Sci Technol., 2004; 15(3-4):137-142; Del Valle, supra; Szejtli J, Szente L., Elimination of bitter, disgusting tastes of drugs and foods by cyclodextrins , Eur J Pharm Biopharm., 2005; 61(3):115-125).
Microencapsulation is a processing technique used in the food, pharmaceutical, and personal care industries. Microencapsulation can isolate compounds from environmental stresses, improve handling and transport of ingredients, control release, add ingredient functionality, and mask unwanted odors and tastes (Shahidi F, Han X, 1993, Encapsulation of food ingredients , Crit Rev Food Sci Nutr 33(6):501-47; Gibbs B F, Kermasha S, Inteaz A, Mulligan C N, Encapsulation in the food industry: A review, Int J Food Sci and Nutr. 1999; 50(3):213-224; Desai K G H, Park H J, 2005, Recent developments in microencapsulation of food ingredients ; Sobel R, Versic R, Gaonkar A G, 2014, Introduction to microencapsulation and controlled delivery in foods , In: A. G. Gaonkar, N. Vasisht, A. R. Khare, R. Sobel, editors. Microencapsulation in the Food Industry. 1st ed. San Diego, Calif.: Academic Press, pp 3-12). Odor and taste masking using microencapsulation is a popular method utilized for functional ingredients with unpleasant sensory qualities, such as iron (Boccio J R, Zubillaga M B, Caro R A, Gotelli C A, Gotelli M J, Weill R, 1997, A new procedure to fortify fluid milk and dairy products with high-bioavailable ferrous sulfate , Nutr Rev 55(6):240-6; Xia S, Xu S, 2005, Ferrous sulfate liposomes: preparation, stability and application in fluid milk , Food Res Int 38(3):289-96), polyphenols (Davidov-Pardo G, Moreno M, Arozarena I, Marin-Arroyo M R, Bleibaum R N, Bruhn C M, 2012, Sensory and consumer perception of the addition of grape seed extracts in cookies , J Food Sci 77(12):5430-8), ginseng (Tamamoto L C, Schmidt S J, Lee S, 2010, Sensory properties of ginseng solutions modified by masking agents , J Food Sci 75(7):5341-7), fish oils (Serfert Y, Drusch S, Schwarz K, 2010, Sensory odour profiling and lipid oxidation status of fish oil and microencapsulated fish oil , Food Chem., 123(4):968-75), and other food products (Del Valle, supra; Szente and Szejtli, supra; Szejtli and Szente, supra).
Microencapsulation involves the incorporation of food ingredients, enzymes, or other materials in surrounding matrices to enhance their stability, target intestinal delivery, or to mask odors and taste (Gharsallaoui A, Roudaut G, Chambin O, Voilley A, Saurel R., Applications of spray drying in microencapsulation of food ingredients: An overview , Food Res Int. 2007; 40:1107). Microencapsulation can be accomplished by physical and chemical means. Physical means include spray drying, spray chilling, spray coating and extrusion, while chemical methods often include cyclodextrin inclusion or liposome entrapment (Gibbs et. al., supra).
Microencapsulation methods differ in the mechanism that they mask or eliminate the unpleasant sensory qualities of functional ingredients. Techniques such as spray drying, can provide a physical barrier of the core to the system in order to reduce taste and odor perception (Shahidi, supra; Gharsallaoui, supra). Other encapsulation methods, such as complexation with cyclodextrins (CDs), can mask the taste and odor of a core through chemical interactions by trapping the core compound within the CD cavity. This chemical complexation can limit or completely inhibit the cores ability to interact with sensory receptors, thereby reducing or eliminating the sensory perception of the core ingredient (Hedges, A R, Industrial Applications of Cyclodextrins , Chem. Rev., 1998, 98:2035-2044; Szejtli and Szente, supra).
It has been observed that microencapsulation has the ability to change the sensory profile of the encapsulated core ingredient (Galmarini M V, Zamora M C, Baby R, Chirife J, Mesina V, 2008, Aromatic profiles of spray - dried encapsulated orange flavours: influence of matrix composition on the aroma retention evaluated by sensory analysis and electronic nose techniques , Int J Food Sci Tech 43(9):1569-76). As a result, the microencapsulated ingredient may not possess the same sensory quality as it did prior to microencapsulation. When included into foods, significant flavor-binding interactions involving wall materials and food components can further modulate the sensory properties of the encapsulated ingredient (Jasinski, E M and Kilara, A, 1985, Flavor binding properties of whey proteins , Milchwissenschaft, 40(7): 596-599; Plug H, Haring G, 1994, The influence of flavor-ingredient interactions on flavour perception , Food Qual Prefer, 5, 95-102; O'Neill T E, 1996, Flavor binding by food proteins: An overview , in: McGorrin R J, Leland J V, eds., Flavor-Food Interactions, Ch. 6, pp 59-74, Washington, D.C.: American Chemical Society; Hansen, A P and Booker, D C, 1996, Flavor Interaction with Casein and Whey Protein , in: McGorrin R J, Leland J V, eds., Flavor-Food Interactions, Ch. 7 pp 75-89, Washington, D.C.: American Chemical Society). Therefore, the knowledge of how a microencapsulated system behaves when included in food and its effect on the sensory properties of the food system as a whole is important for its ultimate utilization in consumer goods.
In order to assess the sensory impact a microencapsulated ingredient has on a food matrix, a variety of sensory testing methodologies, including discrimination tests, can be utilized (Stone, H, Bleibaum, R, Thomas, H A, 2012, Sensory Evaluation Practices, 4th ed., Elsevier Science). Using the rating method, R-index measures can be calculated (Brown J, 1974, Recognition assessed by rating and ranking , Br J Psychol 65(1):13-22) from panelist judgments to determine if a sample containing a known signal, or variable, varies from a noise, or control (O'Mahony M, 1992, Understanding discrimination tests: a user-friendly treatment of response bias, rating and ranking R-index tests and their relationship to signal detection, J Sens Stud 7(1):1-47). R-index measures convey the probability that a participant will notice a difference relative to the control (O'Mahony, supra). The testing methodology is beneficial over traditional discrimination methods for several reasons: 1) multiple comparisons to a single noise can be made, decreasing the amount of tasting overall for samples that are fatiguing and/or available in limited quantities; 2) R-index accounts for response bias, a common psychological error associated with some types of difference testing; 3) R-index measures give quantitative values of the degree of difference related to the control, and not just if overall differences exist (O'Mahony, supra; Lee H S, van Hout D, 2009, Quantification of sensory and food quality: The R-index analysis , J Food Sci 74(6):R57-64)). These measures have been used in pervious literature to observe differences in functional energy drinks (Tamamoto, supra), inulin included milk beverages (Villegas B, Carbonell I, Costell E, 2007, Inulin Milk Beverages: Sensory Differences in Thickness and Creaminess Using R - Index Analysis of the Ranking Data , Journal of Sensory Studies, 22: 377-393), sugar-based products (Urbanus, B L, Schmidt, S J, Lee, S Y, Sensory differences between product matrices made with beet and cane sugar sources , J Food Sci. 2014 November; 79(11):52354-61), and guava beverages (Argaiz, A, Pérez-Vega, O, López-Malo, A, 2005, Sensory Detection of Cooked Flavor Development during Pasteurization of a Guava Beverage Using R - index, Journal of Food Science, 70: S149-S152).
Many humans take a nutritional formula on a regular basis to treat or prevent a nutritional deficiency. The formulas typically contain a balance of proteins, carbohydrates, lipids, vitamins, and minerals tailored to the nutritional needs of the intended user, and include product forms such as ready-to-drink liquids, reconstitutable powders, nutritional bars, and the like. Among the many different kinds of nutritional formulas commercially available today, infant formulas have become particularly well known and commonly used in providing a supplemental, primary, or sole source of nutrition early in life.
Due to the importance of taste in consumer acceptance (Moskowitz H R, Kreiger B, 1993, What sensory characteristics drive product quality? An assessment of individual differences, J Sens Stud 8(4):271-82), the negative odor and taste qualities, along with the solubility issues associated with tributyrin and butyric acid limit its use in food. Despite the advantageous properties of tributyrin described above, direct oral administration has not been feasible because of tributyrin's extremely bitter taste and disagreeable odor (vomit-like, fecal). Accordingly, there is a need for a tributyrin composition with improved sensory properties. More particularly, there is a need for a tributyrin composition that can be orally administered while minimizing or preventing its bitter taste and disagreeable odor. There is also a need for a tributyrin composition that can be delivered to the digestive tract and intestines.